Contradiction with James 3:8
This verse highlights the uncontrollable and unruly nature of the tongue, in contrast to Proverbs 15:4, which speaks of the wholesome tongue as a tree of life.
James 3:8: But the tongue can no man tame; [it is] an unruly evil, full of deadly poison.
Contradiction with Proverbs 18:21
This verse emphasizes that death and life are in the power of the tongue, acknowledging both positive and negative outcomes, while Proverbs 15:4 focuses only on the positive aspect of a wholesome tongue.
Proverbs 18:21: Death and life [are] in the power of the tongue: and they that love it shall eat the fruit thereof.
Contradiction with Matthew 15:11
This verse states that what comes out of the mouth defiles a person, suggesting the tongue's potential for harm, which contrasts with the wholly positive portrayal in Proverbs 15:4.
Matthew 15:11: Not that which goeth into the mouth defileth a man; but that which cometh out of the mouth, this defileth a man.
Contradiction with Job 6:25
This verse speaks of how forceful right words can be, implying that speech can be used powerfully, not only gently, contradicting the gentle imagery associated with a wholesome tongue in Proverbs 15:4.
Job 6:25: How forcible are right words! but what doth your arguing reprove?